Lumbar region of a chair back



FIG. 1 is a front perspective view of a lumbar region of a chair back embodying the present invention;

FIG. 2 is a rear perspective view thereof;

FIG. 3 is a front view thereof, the rear view being a mirror image thereof;

FIG. 4 is a right side view thereof, the left side being a mirror image thereof; and,

FIG. 5 is a top view thereof, the bottom being a mirror image thereof.

The dashed lines in FIGS. 1-5 show environmental structure and do not form a part of the design sought to be patented. 

The ornamental design for a lumbar region of a chair back, as shown and described. 